Aryl mercuric salts of benzene carboxylic acids



Patented June 22, 1937 UNITED STATES ARYL: MERCURIC SALTS OF BENZENE CAR- 7/ BOXYLIO ACIDS Maine No niivFing. I Application mm- 1a, 193:,

- Serial No. sasaos 9 Claims. (c1. 260413) The present invention relates to new organic mercury compounds, particularly aryl mercuric salts of benzene carboxylic acids.

I It is an object of the invention to produce new I organic mercury compounds useful as germicides and for other therapeutic purposes.

I have discovered that when the carboxyl hydrogen atoms of carboxylic acids of benzene and its homologues are substituted by basic radicals 10 of phenylmercury compounds, orcertain, similar aromatic mercury compounds, compounds are produced having high potency as antiseptics and germicides and at the same time are characterized by relatively low toxicity and other desirable properties. My investigations leading to the pro duction of phenylmercury salts of benzoic acid and of polybasic aromatic acids such as phthalic acid, trimesic acid, pyromelliticv acid, mellitic acid and benzenepentacarboxylic acid, have shown that these salts possess extraordinarily high potency as germicides. It vhas furthermore been observed that the greater the number of carboxy groups of the acid used, and hence the greater number of phenylmercury radicals that may be substituted, the greater is the germicidal potency of the resulting salt. This and other observations made by me have confirmed my belief that the aromatic mercury salts of the carboxylic acidsof the polynuclear aromatic hydrocarbons, e.: g.,

naphthalene, anthracene and 'phenylanthracene are likewise characterized by highly satisfactory germicidal properties and such compounds are included within the scope of my invention.

The compounds constituting the subject matter of the present invention may be described as having the general formula (RI- 1g) :31, in which R represents an aromatic structure, which maybe an aromatic nucleus with or without side chains:

and in which none of the nuclear or side chain 40 carbons has direct linkage with any element other than hydrogen, carbon and mercury; in which a: is an integer having a value of 1 or more; and in which R1 represents an aromatic hydrocarbon acid radical which may have one or more 0001-1 groups that is linked to a RI -Ig' group or groups through replacement of a carboxyl hydrogen atom or atoms. R may stand for the phenyl group, CsHs, or for an aromatic hydrocarbon having a nucleus similar to the phenyl hydrocarbons, as for example, polycyclic hydrocarbons in which all the nuclear carbons other than the one attached to mercury, and any side chain carbons, have their valences satisfied by carbon orhydro gen. Examples are the paradiphenyl groups. The expression aromatic structure as used herein is intended to be generic andinclude anaromatic nucleus with or without side chains.

While'the word group is used hereinafter, it 20 V will be understood that it must be interpreted as plural when the value of a: is more than one. v

The compounds may be prepared in various ways. The following specific examples illustrate the invention: I l 25 ExampleI I I 2.94 grams of phenylmercury hydroxide were dissolved in 1 liter of water by' heating to boiling. The solution was then filtered to remove any 30 gums orfother insoluble material present. Tofthe filtrate was added an aqueous solution containing 1.34 grams-of benzoic acid. The resulting 'mix ture was then heated to boiling and then allowed to cool and stand until precipitation was com-' 35 plete. The precipitate after filtration was washed 1 thoroughlywith water and dried. The resulting product is a white crystalline product which is sparingly solublein'water. It melts at 94 C. and conforms to the formula CaHsHgOOQCaI-I for 40 phenylmercury benzoate. V

Example 2 17.64 grams of phenylmercury hydroxide were dissolved in 4 liters of water. The mixture was U filtered and to the filtrate was added 4.87, grams of phthalic anhydride in aqueous solution. The mixture was brought to boiling and then allowed to cool and stand until precipitation was com-- plete. The precipitate was then washed with dis- C. It coniorms totheiormula a white crystalline substance sparingly soluble in water and melting at 217". It conforms to the formula CsH4.(CO0HgCsHt)s i'or phenylmencury Example 3 I 17.64 grams oi phenylmercury hydroxide were dissolved in 4 liters of water and themfiltered. To

the filtered solution was added anaqueous solu 1 tion 01' 4.62 grams oi trimeslc acid. The solution was broughtto boiling and then allowed to stand for 24 hours; The precipitate was filtered oil, washed and dried. The resulting product is a white crystalline substance melting above 4 otmlcoons'ctmn for phenylmercury trimesate. Example 4 a 14.7 grams of phenyhnercury hydroxide {were 1 dissolved in 4 liters of water by heating to 1 0 1 118.

The solution was filtered and to the filtrate was i added anaqueous solution'oi. 4.46 grams; oi benzenej pentacarboxylic acid; The r ture'washeated .to boiling and thenicooled and allowed to stand for 24hours before filtering.v The with thesalts formed. no dimculty is encountered in washing the salt preclpitateiree from theJexcess acid.

. In the examples,-the method employed is the general neutralization method oi reacting abuse with an acid to produce a salt and watch; .The application 50!. this method to the preparation 01' phenylmercury'asalts of organic acids is being claimed in my co-pending application Serial No.

'694,l98,.filed October 18, 1933. This method has theadvantage that the only by-product of the re- I actionf'is water. a

' I e e zmetnoe that maybe em w p p ring these salts is the O-ca,1]ed prec1p1tation'method'wherein a phenylmercury salt oi an organic acid, e. g., phenylmercury acetate, is re-L I acted with an acid capable of .forming phenylmercurysaltsof relatively low solubillty"as*compared withthe salts-of the first acid and that are also relativelyinsoluble as compared with the first v acid' itself, This general methodas'applied'to the preparation of phenylmercury'salts of organic acids generally is described and claimed in my co pendi'ng application BerialfNo. 694,199,

filed October 1a, 1933. s

. All or the compounds produced as above de- V scribed are characterized by highly satisfactory antiseptic .and germicidal properties.

Tests to determine the efllcacy of the phthalate and the benzenepentacarboxylate in killing B. tuphoims and Staph. aureus were carried on under the following conditions: v I Aqueous solutions of varying dilutions irom 1:10.000 upward until killing ceased were made 4 aoasgan tilled water and dried. The resulting product 'is up. These dilutions were. employed in the conductor the tests by the following methods: .Circular 198, U. B. Dept.--oi- Agriculture, Dec. 1931, described as I". D. A. method against lberthella typhi (typhoid bacillus) at 8'! C. and I". D. A."

special method against Staph. aureus at 8'! 0..

' The maximum dilutions at which killing-in 16 minutes resulted are giwn below:

l'hen lines-wry hthalate.--. -'..-i.... 1: "an i! one rhen lmermry enssuspentsesgbosylste un touo 1:18

Tests solar conducted with theoth er cornto those of'the phthalate oi the benaenepentacarbonlate. The potency-oi the bensoatei-is somewhat below that of the phthslate but-is.

. pounds above mentioned indicate that. with the v. exception oi the benzoate, they possess germi-i 'cidal propertiesthatareint'ermediateindegree nevertheless high as compared to most germi- 1 sides heretofore available. All of these compounds are characterized by relatively low tox-I icity. Because oithis-and 'their highpotency which makes it possible to usethem-in extreme dilutions they maybe usedlocally in most cases and in some cases a internally with satisfactory results from: the germicidal standpoint and without harmful eilects. H

'These new compounds may be used directly as germicides in aqueous or other solutions or may be iormed into various preparations such as mouth washes, tooth pastes, soaps, etc. and such compositions :are considered to be-within the scope oi the invention as defined in the appended claims. s

l. Anew organic "mercury compound oi the general formula (RHghB-i, in which R represents an aromatic structureyandin which none of the carbon atoms has direct linkage with any element other than hydrogen, carbonJand mercury; in which R1 represents the'radical of an acid selected from, the group'consisting o! the carbonlic acids of benzene and its homologues, which radical is linkedto the RJ-Ig group through replacement of the carboxylhydrogen; and in which a: is an integerhaving a value of at least 1 and not more than the number of carboxyl hydrogens in the acid. 1

.2. A new organic mercury compoundoi. the general formula (RHg)'=.-Rx. in which R repre sents an'aromatic structure, and in which none or the carbon atoms has direct linkagev withanyv element other than hydrogen. carbon and mer- I cury; in which R1 represents the acid radical oi,

an unsubstituted carboixylic' acidot benzene that is linked to the RHg group through replacement or the carboxyl hydrogen; and-in which :n is an integer having a.value or at least 1 and not more tlinan the number of carb'ox'yl hydrogens. in the ad.

3. A new organic mercury; compound or the general formula (RHg )'=.R1.in which Rrepresents an aromatic'nu'cleus. and in which none of the" carbon atoms has linkage with any element otherthan hydrogemcarbon and mercury; in which R1 represents the acid radicaloi anunsubstituted} polybasic "carboxylic acid of benzene that is linked to the RHg groupthrough,

replacementoi the carboxyl hydrogen; an'din which :sisan integer having a value of at least.

6. A phenylmercury salt of an unsubstituted carboxyllc acidof benzene.

7. Phenylmercury phthalate;

8. Phenylmercury trtmesate.

9. Phenylmercury benzenepentacarboxylate; x 5 I dc CARL N. ANDERSEN. 

